THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
# ulimit -n 32768
# ulimit -u 65536
# echo -e "* - nofile 32768\n* - nproc 65536" >> /etc/security/limits.conf
- Disable IPv6, leaving it enabled may force service to bind to IPv6 addresses only and thus resulting in inability to connect to it ([source link](https://wiki.centos.org/FAQ/CentOS6#head-d47139912868bcb9d754441ecb6a8a10d41781df)):
...
# echo -e "\n# Disable IPv6\nnet.ipv6.conf.all.disable_ipv6 = 1\nnet.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.conf
...
- Disable Transparent Hugepage. Add "{{transparent_hugepage=never}}" to the end of the kernel line in "/etc/default/grub" and reboot. (Ambari demands it, do we need to comply?):
```
Change the line:
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=cl/root rd.lvm.lv=cl/swap rhgb quiet"
To:
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=cl/root rd.lvm.lv=cl/swap rhgb quiet
transparent_hugepage=never"
Afterwards, run:
# grub2-mkconfig -o /boot/grub2/grub.cfg
```
...